Building resilience in the city

Urban agriculture is an ancient practice that must adapt to a changing climateIsabelle Anguelovski

Urban farmers have dealt with changing climates for as long as there have been cities. In fact, the world's first cities in Mesopotamia probably developed for the purpose of practising agriculture around a central irrigation system during an earlier period of volatile climate. Urban agriculture can be a valuable response to climate uncertainty and a crucial part of a resilient city. However, city-dwelling farmers in the developing and developed world alike face their own challenges from climate change. If urban agriculturists are to enable their cities to be resilient they also must find resilience for their own farms.

Seeking water in Beijing

While not quite as ancient as the first cities of Mesopotamia, Beijing has been a major centre for millennia, and the Chinese capital has probably never been without a large agricultural fringe. Today, however, the city is in the ninth year of a drought that climate experts suspect may represent a new trend. As rainfall and the water table decline, agriculture, which represents about one third of the city's water use, is facing uncertainty: the groundwater used for almost all irrigation is becoming unavailable in some areas and in 2007 the city instituted a fee for excessive agricultural use.

To remain resilient, Beijing's farmers are looking for ways to diversify their water sources, and two approaches have been borrowed from Chinese agriculture's long history. Beijing's wastewater was often reused for irrigation in the distant past, and the practice has revived since 2000 with the municipal government distributing water from the central treatment plant: in 2007, 20 per cent of irrigation requirement was met with wastewater, but only in areas near the plant. The other technique, rainwater harvesting, is being introduced by the NGO SWITCH, which has been helping farmers modify greenhouse roofs to gather rain for the past four years. "Rainwater harvesting technologies have been applied for many years in the northwest of China," explains Ji Wenhua of SWITCH, "but most of the systems in Beijing have been built since 2005. There are now hundreds of sites with rainwater harvesting and most of them are in active use."

Coping in Quito

Located on hillsides surrounding Quito, urban farmers are often poor and marginalisedIsabelle Anguelovski

A world away, Quito, Ecuador provides an example of the challenges facing urban farmers with little municipal integration or recognition. Located high in the Andes, Quito is surrounded by communities growing crops in small plots across some 64 hillsides encircling the city. The region is facing higher temperatures and droughts, and when rain does come it is increasingly as heavy storms causing landslides on the steep slopes.

While in Beijing urban agriculture has achieved recognition as a major part of the economy and food supply, in Quito it is the domain of the poor and marginalized, growing to support their households and maintain food security. While the city is a leader in climate change planning, says Isabelle Anguelovski, a researcher from the Massachusetts Institute of Technology, "Agriculture has been quite independent, up to now, of the climate discourse in Quito. The priorities of the climate discourse have really been water provision, risk management, and biodiversity protection."

With limited official support*, farmers have nevertheless begun to adapt. In many plots, corn and potatoes have given way to indigenous Andean crops such as quinoa, which require less water and hold the soil against erosion. Farmers along the streams flowing from the shrinking Antisana Glacier are also adopting more conservation measures for water use and protecting key ecosystems in the watershed. Such measures build resilience at the grassroots, but greater support from the city is needed.

A new urban tomato

AVRDC is breeding new varieties of tomato that are able to handle harsher climatesAVRDC

In every city around the world, urban farmers depend on vegetables. These high value crops can be the most profitable use of small urban plots, and being difficult to transport, resilient cities need vegetable farms near at hand. Foremost among these urban staples is the tomato. Unfortunately tomatoes, being 95 per cent water, are hard hit by heat and drought, and AVRDC, the World Vegetable Center, is now seeking to breed tomatoes that can handle harsher climates in urban situations.

The breeding project is global in scope, crossing tomatoes with their wild relatives. One, Solanum chilense, from the deserts of Chile, grows a much larger root system and does not wilt in the heat. Another, Solanum pennellii, is an efficient water user, and can even absorb dew through its leaves. The research team, led by Dr. Robert de la Peña, is tapping into these natural sources of resilience. The new varieties are already allowing farmers in the tropical lowlands to grow tomatoes during the hot-wet season for the first time ever, and should prove valuable to urban agriculturists facing the sorts of challenges seen in Beijing and Quito. Along with water, land, and recognition in urban planning, the plants available to urban farmers are keys to their resilience in a changing world.

*The city has begun supporting urban farmers through a dedicated office, AGRUPAR (Agricultura Urbana Participativa), but its function is limited to technical assistance; it is not integrated into larger municipal functions or planning.